In this prospective study on patients with acute myocarditis (AM), we aimed to describe the new concept of AMAF (AM with autoimmune features) similar to the previously described interstitial pneumonia with autoimmune features (IPAF). IPAF has recently emerged as a new entity, and IPAF patients appear to have fewer episodes of exacerbation and better survival than patients with idiopathic pulmonary fibrosis. Consecutive patients with infarct-like CMR-confirmed AM were classified AMAF if their serologic status measured from blood sampled at presentation was positive (antinuclear antibodies (ANA) ≥ 1:320), but without meeting established classification criteria for connective tissue disease (CTD). The myocardial tissue abnormalities and their progression were assessed on cardiac magnetic resonance (CMR) within 7 days following symptom onset and at 1 year according to their seropositivity. Among the 64 AM patients included, seven presented AMAF (11%). At baseline CMR, patients with AMAF had half as much late gadolinium enhancement (LGE) as seronegative AM patients (4.41% (1.47–4.41) of myocardial volume versus 8.82% (5.88–14.71), p = 0.01, respectively). At 1-year of follow-up, persistent myocardial scarring was less frequent in AMAF patients (n = 2 (28.6%) than seronegative AM patients (n = 38 (66.7%) (p = 0.021). AMAF, diagnosed as seropositive AM without a specific autoimmune disease, is not rare and is associated with less extensive LGE in the acute phase. In addition, AMAF patients had more favorable outcomes on 12-month CMR. Prospective studies are needed to address the clinical significance of this new concept and its long-term cardiovascular impact.

在这项针对急性心肌炎 (AM) 患者的前瞻性研究中，我们旨在描述类似于先前描述的具有自身免疫特征的间质性肺炎 (IPAF) 的 AMAF（具有自身免疫特征的 AM）的新概念。IPAF 最近成为一个新实体，与特发性肺纤维化患者相比，IPAF 患者的恶化发作次数似乎更少，生存率更高。如果在就诊时从血液样本中测量的血清学状态为阳性（抗核抗体 (ANA) ≥ 1:320），但不符合既定的结缔组织病 (CTD) 分类标准，则连续患有梗死样 CMR 确认的 AM 患者被分类为 AMAF . 心肌组织异常及其进展在症状出现后 7 天内和 1 年内根据其血清阳性进行心脏磁共振 (CMR) 评估。在包括的 64 名 AM 患者中，7 名出现 AMAF（11%）。在基线 CMR 时，AMAF 患者的晚期钆增强（LGE）是血清阴性 AM 患者的一半（4.41%（1.47-4.41）的心肌体积对 8.82%（5.88-14.71），p  = 0.01，分别）。在 1 年的随访中，AMAF 患者（n  = 2 (28.6%) 比血清阴性 AM 患者 ( n  = 38 (66.7%) ( p  = 0.021)）中持续性心肌瘢痕形成的频率更低。AMAF，诊断为血清阳性 AM没有特定的自身免疫性疾病，并不罕见，并且与急性期 LGE 较少相关。此外，AMAF 患者在 12 个月的 CMR 中具有更好的结果。需要前瞻性研究来解决这一新概念的临床意义和对心血管的长期影响。